The main foundation of a nacelle is adapted to at least transfer the loads and forces from the main axle of the wind turbine to the yaw bearing of the wind turbine. The rear frame is adapted to support different wind turbine components arranged inside the nacelle and is furthermore adapted to support other elements arranged inside the nacelle, for instance an overhung crane structure.
The rear frame is connected to the main foundation, enabling loads and forces from the different components and other elements being supported by the rear frame to be transferred to the main foundation via the connection to the yaw bearing of the wind turbine.
Accordingly, it is essential that the connection between the main foundation and the rear frame is solid to facilitate transfer of loads, forces and torques via this connection.
In some prior art solutions, the connection between the main foundation and the rear frame comprises bolt connections. However, in these prior solutions, the connection has proven to be less stable than desired, which causes unintended loads to the connection.